Re: Interrupt handling and routing: The Big Picture

[Frank Wille <frank%phoenix.owl.de@localhost>]

On Tue, 13 Mar 2012 00:02:07 +0100
Jochen Kunz <jkunz%unixag-kl.fh-kl.de@localhost> wrote:

> > I wonder if this FEC is compatible with the ColdFire FEC?
> > But probably not, when BestComm is involved.
> I don't know the ColdFire FEC.

I had a quick look. It's probably just the same name.


> Do we have code for it in tree?

For ColdFire? Unfortunately not. But when this type of FEC is also used
by other CPUs/SOCs then the driver should go to /dev.


> > Maybe newer CPUs with critical interrupts should be handled like in
> > powerpc/booke/e500_intr.c ?
> Well. It looks like I can programm the PIC so that it only generates
> standard interrupts...

Hm. Really? I had a glance at the interrupt routing diagram in the UM
yesterday, and it looked like some devices can only deliver critial
interrupts.


> Yes. But the hwirq is just an int number. The MPC5200 PIC has four
> types of interrupts: Peripheral, External, Main and BestComm. All
> these interrupts are numbered starting at 0. So I have to do some
> things like: hwirq 0..31 is External, 32..63 is Main, 64..95 is
> Peripheral, 96..112 is BestComm. At least the OpenFirmWare seems to
> do something like this. [...]

Yes. You can use any hwirq number you like. Just your PIC driver needs
to perform the right actions on it.

-- 
Frank Wille